Quadruple-U Auxiliary Structure-Based Receiving Coil Positioning System for Electric Vehicle Wireless Charger

Round 1

Reviewer 1 Report

In this paper, a receiving coil positioning approach integrated with a quadruple-U auxiliary structure is proposed. The designed quadruple-U auxiliary structure with cruciform distribution consists of four U-shaped coils, which are inspired by the solenoid coil. Based on the symmetry of the auxiliary structure, a receiving coil positioning method is proposed by measuring the load voltages of each U-shaped coil working in dependently. Furthermore, the specific magnetic coupler is simulated by a three-dimensional finite element modeling tool and verified by experiment on a prototype. During the positioning process, positioning range was tested. Experimental results indicate that all the tested positions are accurate to within 10mm with a 160mm transfer distance. 

In this way, the work presents a very relevant and current theme. The research was very well conducted, and the work is well written and structured. The simulations were carried out properly, as well as the experimental part, which contributes significantly to a better understanding of the results obtained. However, I still indicate that the summary and conclusions be revised in order to bring more information about the work carried out. I also suggest improving the bibliographic references, seeking more up-to-date references.

The work is well-written, and English is well-used. I didn't notice any significant errors, so I don't think a review in English is necessary.

Author Response

Thank you for your valuable suggestions for revision. According to your opinions, the abstract and conclusion have been revised, and the bibliographic references have been improved.

Reviewer 2 Report

1. To insist the novelty of the proposed U-shaped coil, the authors should give more comparision between other shape of coil. The comparison table or discussion part can be introduced.

2.  To support the effectiveness of the proposed system, the experimetal waverform supporting the output voltage and current should be included in the article. Also, the WPT efficiency acrroding to the M or Pout should be given.

1. WEVJ is international journal, so the legen in Fig.14 should be corrected to the english.

Author Response

Thank you for your valuable suggestions for revision. According to your opinions, we have made corresponding modifications. Please check the attached file for details.

Author Response File: Author Response.docx

Reviewer 3 Report

The paper is proposing a new type of device based on mutual inductance detection and data processing for addressing the very common issue of misalignment between the emitting and receiving circuits of an electric vehicle wireless charger. The authors propose a dedicated structure to perform the alignment stage prior to the actual charging process. The proposed solution relies on four identical U-shaped ferrite coils arranged in a cross-like disposition.

The following general remarks can be expressed:

1.      How did the authors decide upon the actual number of four U-shaped coil components and their particular placement? Was this choice a result of an optimization process or just a result of an empirical trial and error process guided by the authors’ technical skills? Essentially, the proposed method relies on the detection and control of four mutual inductances between the four U-shaped coils and the receiving circuit. In my opinion, the task of simultaneously managing four distinct mutual inductances is extremely challenging, requiring significant measuring and processing equipment. Moreover, the misalignment data must be processed to be displayed in an accessible manner to the car’s driver, who is supposed to correct the misalignment to less than a centimeter of accuracy. That would imply an extremely skilled driver, certainly not an average one, a fact that is rather improbable in practice. Additionally, having in view that the method relies on the measurement and combined interpretation of four mutual inductances, why not adopt a simpler mutual inductance measurement, namely that of the emitting and receiving circuits themselves? That would require the detection and control of a single mutual inductance in order to maximize its value (corresponding to a perfect alignment). Moreover, no additional pre-alignment circuitry is needed.

 

2.      There are many notation inconsistencies, not defined abbreviations, grammar errors, and typos. All that and more specific targeted remarks are contained in the hereby attached PDF manuscript itself as comments (35 in total). Please refer to it.

Comments for author File: Comments.pdf

All the identified grammar errors and typos are marked on the actual PDF manuscript.

Author Response

Thank you for your valuable suggestions for revision. According to your opinions, we have made corresponding modifications. Please check the attached file for details.

Author Response File: Author Response.docx

Reviewer 4 Report

In this paper, the authors propose a design, analysis and real test of  receiving coil positioning approach, integrated with a quadruple-U auxiliary structure. The proposed a quadruple-U auxiliary structure with cruciform distribution is proposed to assist in the vehicle enter into the effective charging area.

Based on the design results, a mutual inductance analysis under different misalignment was made and a positioning approach algorithm was developed.

It is necessary to remark that authors was built a wireless charging system prototype with the proposed quadruple-U auxiliary structure and LCC-S compensation circuit in order to illustrate the positioning feasibility in the range of ΔX∈[-300mm, 300mm]∩ΔY∈[-300mm, 300mm].

Some things need to be clarified:

1.      What is the actual distance between transmitting and receiving coils - page 4, line 29 - 100 mm, and on page 15, line 14; page 16, row 4 - 160 mm?

2.      The third point is "WPT System Based on the Triple-U Auxiliary Coil", and mainly rectangular receiving coils are considered - fig.4,  fig. 11, fig. 13.

3.      It is good to comment on the action of the proposed positioning system when the transmitting and receiving coils are not parallel, but are located at a certain angle, which is very close to the practical application in electric cars.

4.      References cannot be cited in block (eg. [1-3],[18-19], [23-24]). For each of them it is necessary to describe which aspects are significant for the paper.

5.      To comment on the choice of frequency (why is it around 95khz) because this value is of great importance for the accuracy and geometrical parameters of the developed positioning system.

Author Response

Thank you for your valuable suggestions for revision. According to your opinions, we have made corresponding modifications. Please check the attached file for details.

Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

The authors have answered to my concerns and corrected most of the errors present in the text. I have no further remarks.

The English language quality is satisfactory.